Optoelectronic semiconductor chip

Abstract

In one embodiment, the optoelectronic semiconductor chip includes a semiconductor layer sequence with an active zone for generating radiation with a wavelength of maximum intensity L. A mirror includes a cover layer. The cover layer is made of a material transparent to the radiation and has an optical thickness between 0.5 L and 3 L inclusive. The cover layer is followed in a direction away from the semiconductor layer sequence by between inclusive two and inclusive ten intermediate layers of the mirror. The intermediate layers alternately have high and low refractive indices. An optical thickness of at least one of the intermediate layers is not equal to L/4. The intermediate layers are followed in the direction away from the semiconductor layer sequence by at least one metal layer of the mirror as a reflection layer.

We claim: 
     
         1 . An optoelectronic semiconductor chip comprising;
 a semiconductor layer sequence having an active zone for generating radiation with a wavelength of maximum intensity L; and   a mirror for the radiation on a rear side opposite a light extraction side, wherein   the mirror comprises at least one cover layer,   the cover layer is formed with a material transparent to the radiation and has an optical thickness of at least 0.5 L inclusive,   the cover layer is followed by several intermediate layers in a direction away from the semiconductor layer sequence,   the intermediate layers have alternately high and low refractive indices for the radiation and are each made of a material transparent to the radiation,   the intermediate layers are followed in the direction away from the semiconductor layer sequence by at least one metal layer, and   the metal layer extends through the intermediate layers and the cover layer towards the semiconductor layer sequence.   
     
     
         2 . The optoelectronic semiconductor chip according to  claim 1 , wherein the metal layer is configured to apply a current to the semiconductor layer sequence. 
     
     
         3 . The optoelectronic semiconductor chip according to  claim 1 , wherein the metal layer is configured to apply a current to a p-doped side of the semiconductor sequence. 
     
     
         4 . The optoelectronic semiconductor chip according to  claim 1 , wherein the metal mirror layer comprises or consists of silver or a silver alloy. 
     
     
         5 . The optoelectronic semiconductor chip according to  claim 1 , wherein the metal mirror layer comprises or consists of gold or aluminum or a gold alloy or an aluminum alloy. 
     
     
         6 . The optoelectronic semiconductor chip according to  claim 1 , wherein between the cover layer and the semiconductor layer sequence a contact layer is arranged,
 wherein the metal mirror layer is directly contacting the contact layer.   
     
     
         7 . The optoelectronic semiconductor chip according to  claim 6 , wherein the contact layer comprises or consists of a transparent conductive oxide. 
     
     
         8 . The optoelectronic semiconductor chip according to  claim 6 , wherein the contact layer comprises or consists of indium tin oxide, indium zinc oxide or zinc oxide. 
     
     
         9 . The optoelectronic semiconductor chip according to  claim 6 , wherein the intermediate layers, the cover layer and/or the contact layer are structured by means of a dry etch process. 
     
     
         10 . The optoelectronic semiconductor chip according to  claim 6 , wherein the contact layer is arranged directly at a p-doped side of the semiconductor layer sequence. 
     
     
         11 . The optoelectronic semiconductor chip according to  claim 1 , wherein the metal layer directly contacts the semiconductor layer sequence. 
     
     
         12 . The optoelectronic semiconductor chip according to  claim 1 , wherein the cover layer has a thickness of at most 5 L. 
     
     
         13 . The optoelectronic semiconductor chip according to  claim 1 , wherein the metal layer is configured as a reflection layer for radiation generated in the active zone. 
     
     
         14 . The optoelectronic semiconductor chip according to  claim 1 , wherein a thickness of at least one of the intermediate layers is unequal to L/4. 
     
     
         15 . The optoelectronic semiconductor chip according to  claim 1 , wherein the cover layer has an optical thickness between 1.1 L and 1.6 L, inclusive. 
     
     
         16 . The optoelectronic semiconductor chip according to  claim 1 , wherein the cover layer is of SiO 2  and/or the intermediate layers are alternately of Nb 2 O 5  and SiO 2 . 
     
     
         17 . An optoelectronic semiconductor chip comprising:
 a semiconductor layer sequence having an active zone for generating radiation with a wavelength of maximum intensity L; and   a mirror for the radiation on a rear side opposite a light extraction side, wherein   the mirror comprises at least one cover layer,   the cover layer is formed with a material transparent to the radiation and has an optical thickness of at least 0.5 L inclusive,   the cover layer is followed by several intermediate layers in a direction away from the semiconductor layer sequence,   the intermediate layers have alternately high and low refractive indices for the radiation and are each made of a material transparent to the radiation,   the intermediate layers are followed in the direction away from the semiconductor layer sequence by at least one metal layer as a reflection layer,   the semiconductor chip comprises at least one through-connection extending from the metal layer to the semiconductor layer sequence,   the through-connection electrically connects the metal layer and the semiconductor layer sequence, and   the through-connection and the metal layer are formed in one piece.   
     
     
         18 . An optoelectronic semiconductor chip comprising:
 a semiconductor layer sequence having an active zone for generating radiation with a wavelength of maximum intensity L; and   a mirror for the radiation on a rear side opposite a light extraction side, wherein   the mirror comprises at least one cover layer,   the cover layer is formed with a material transparent to the radiation and has an optical thickness of at least 0.5 L inclusive,   the cover layer is followed by several intermediate layers in a direction away from the semiconductor layer sequence,   the intermediate layers have alternately high and low refractive indices for the radiation and are each made of a material transparent to the radiation,   the intermediate layers are followed in the direction away from the semiconductor layer sequence by at least one metal layer as a reflection layer,   between the semiconductor layer sequence and the cover layer a contact layer is arranged at direct contact with the semiconductor layer sequence,   the contact layer is made of a transparent conductive oxide,   the semiconductor chip comprises at least one through-connection extending from the metal layer to the contact layer,   the through-connection electrically connects the metal layer and the contact layer, and   the through-connection and the metal layer are formed in one piece.   
     
     
         19 . The optoelectronic semiconductor chip according to  claim 18 , further comprising an adhesion promoting layer arranged between the metal layer and the intermediate layers, between the through-connection and the intermediate layers, and between the through-connection and the contact layer,
 wherein the adhesion promoting layer overmolds the through-connections, and   wherein the adhesion promoting layer and the contact layer are made of the same materials.   
     
     
         20 . The optoelectronic semiconductor chip according to  claim 18 , further comprising an adhesion promoting layer arranged between the metal layer and the intermediate layers, wherein the through-connection is free of the adhesion promoting layer.